Associations of cigarette smoking with RA disease severity measures
| Disease severity measure | Number of subjects |
Pack years of smoking Mean (SD) (median) | p Value2-150 |
| Rheumatoid factor | |||
| Positive | 213 | 18.46 (23.37) (9.55) | 0.0001 |
| Negative | 123 | 9.66 (19.97) (0) | |
| Radiographic erosions | |||
| Present | 241 | 16.77 (22.71) (4.5) | 0.024 |
| Absent | 95 | 11.33 (21.77) (0) | |
| Subcutaneous nodules | |||
| Present | 115 | 17.21 (22.78) (7.47) | 0.051 |
| Absent | 121 | 14.21 (22.41) (0) |
↵2-150 Wilcoxon rank sum statistic.